Voltage regulator



Aug. 10, 1937. J. 1.. SCHERMERHORNV VOLTAGE REGULATOR Filed 00f.. 6,1936 3 Sheets-Sheet 1 INVENTOR $512 Z- SZZermer/farn BY I % ATTORNEYAug. 10, 1937;

J. 1.. SCHERMERHORN VOLTAGE REGULATOR Filed Oct. 6, 1936 Sheets-Sheet 2INVENTOR 02/97; zazzermfizmm ATTORNEY 1937. J. L. SCHERMERHORN'2,089,434

VOLTAGE REGULATOR Filed Oct. 6, 1936 s Sheets-Sheet is INVENTOR $77z-Afi'zerzwer'k ry ATTORNEY Patented Aug. 10, 1937 UNITED STATES VOLTAGEREGULATOR John L. Schermerhorn, East Orange, N. J., as-

signor to American Transformer Company,

Newark, N. J.

Application October 6, 1936, Serial No. 104,176

9 Claims.

This invention relates to a voltage regulator which includes atransformer having a core and winding thereon preferably arranged in theform of an auto-transformer. In many respects my .5 present regulatorhas many characteristics in common with the voltage regulators shown anddescribed in Hunter paterits 1,993,007, issued March 5, 1935; and2,014,570, issued September 17, 1935.' However, the regulator to behereinafter described is designed more particularly for smaller currentsor watt capacity.

It is the principal object of my present invention to provide arelatively low-wattage voltage regulator which will give exceedinglyclose 35 voltage regulation at high effic'iency; and a regulator that ischeap to manufacture yet one that is strong and durable.

Other advantages Will be discerned by one skilled in this art, from areading of the specifi- 20 cation, taken in connection with the annexeddrawings, wherein Figure l is a part-elevational and part-sectional viewthrough the regulator, certain parts being removed or omitted from theview to better illustrate the other parts.

Figure 2 is a top plan view of Figure 1, but on a reduced scale, withall the parts positioned, except the cover which is shownin dotted line.

Figure 3 is a bottom view of Figure 1, with all 39 the parts positioned,except the cover which, as

in Figure 2, is shown in dotted line.

Figure 4 is a view on the line 44 of Figure 1.

Figure 5is a view on the line 55 of Figure 1.

Figure 6 is a view of the brush holder such as 35 shown in Figure l butof a slightly modified method of making connection to the brush holderper se.

Figure 7 is a detailed perspective view to illustrate the contact of thebrush with the winding. 40 Figure 8 is a side elevation of a modifiedform of brush holder.

Figure 9 is a view of Figure 8 looking at the spring side of the holder.

Figure 10 is a view of the brush holder per se,

45 looking from right to left of Figure 8.

Figure 11 is an end view of the bottom part of figure 8.

Figure 12 is an elevational view of a polyphase regulator; that is tosay, one using a plu- 59 rality of units shown in Figure 1.

Referring now to the details, wherein like numbers refer tocorresponding parts in the various views, I is the core of a ring typetransformer. As shown, the core I is preferably 55 made up of a singlestrip of silicon steel ribbon spirally wound into ring form, although itwill be understood that the core I may be constructed in other ways; forexample, it may be made out of discs or washers punched from suitablesheet stock, but a core of this construction is very wasteful inmaterial. The spirally wound ring core has another very specialadvantage over a stack of discs in that, with the discs, it is necessaryto provide an insulating tube fitting tightly over the outer surfaces ofthe discs as a back 10 support for that part of the winding which actsas a brush track or commutator. Where the core is made out of a singlepiece of steel ribbon, spirally wound, it provides a very solid backsupport so that the special insulating cylinder is 15 not required, butthe core may be exteriorly wound with sheet insulation which is wrappedtightly around it and treated with a suitable insulating varnish orequivalent. This is less expensive than the special tube and makes amore satisfactory construction. This insulation around the core isindicated by the numeral 2.

Wound over the insulation 2 is awinding 3 which is of a suitable sizewire chosen according to the watt capacity of the regulator. The

winding 3 is preferably cottonor fabric-covered, enamel Wire, which Ihave found far preferable to plain enamel wire, because the turns arebetter insulated, and the fabric covering will absorb the insulatingvarnish or equivalent, making the whole winding moisture-proof and moredurable than the winding of plain enamel wire. After the core I has beenwound with the winding 3, I apply, to the exterior circumferentialsurface thereof, a pair of spaced bands 4 and 5 which are preferablymade of'treated insulating material, to prevent expansion and whichserve a plurality of purposes, in one of which the bands, which arepreferably made up of a plurality of turns of. treated fabric, preventexpansion of the winding, thereby serving to hold the brush orcommutator section 6 securely in place between the bands, under normaloperation of the movement of the brush over the track, it beingunderstood that the insulation is removed from the winding between thebands 4 and 5 to leave a bare track surface or commutator section 6. Thebands also act to prevent movement of the wires or conductors at thetrack or commutator section when pressure is appliedto the transformerstructure by the holding-down clamps. The bands 4 and 5 also act toprevent the brush holder, to be later referred to, from coming intoengagement with the the bare conlar manner, the bottom spider I hasthree spaced arms extending outwardly, each having a curvilinearly'shaped seat to engage insulators ll around the bottom edge of thetransformer.

The spider [has a hub it which is adapted to flt over the end of thetubular member I. which is threaded at- II to receive a clamping nut IIwhich, when set up, securely clamps the transformer between the twospiders I and I. The

arms of the spider I have extensions 'or feet i1,

having-holes ll therein for mounting the regulator on a suitablesupport. Also, these extensions are provided with shoulders I! forreceiving and supporting an outer case l1. which has been indicated indotted-lines and which serves to completely enclose the regulator whennecessary. Also, the arms of the spider I have flanges is positioned toreceive devices used in connection with the regulator.. For example, byreference to Figure 3, one pair ofthe flanges II have attached thereto,by screws", a terminal strip Ii of insulating material carrying contactstuds H, II and 24. It may be noted that to the terminals "and", areconnected the ends of the winding 3. Another pair of flanges ll carriesa name plate 2!, on which the usual data or indicia is aiilxed. It is tobe noted that the arms of the spider I have ribs 28 to furtherstrengthen the said arms. The use of thisstyle of clamps has severaladvantages over solid plates, in that free circulation of air isprovided through the inside of the regulator for cooling purposes. Inaddition, the construction described reduces the weight and assists inaccurately lining up the core with, the shaft mounting, to be laterdescribed.

Located in the bottom end of the tubular member I0, is a'shoulderedbushing 21 which is centrally bored to receive one end of an operatingshaft 28, the bushing being fastened to the shaft 2| by a set screw 20.Mounted in the top part of the cylindrical member II is anothershouldered bushing 80, through which" the shaft 28 passes and isfastened to the bushing ilibya set screw II. The top part of the shaftcarries an operating hand-wheel M; The bushing '30 has an arm 82 whichmay be integral therewith, or which may be fastened thereto. The arm 32extends radially outwardly over the top of the transformer and, at itsextremity, there is fas- .tened'a depending member 33, at the lower endof which is fastened, in any satisfactory manner, as by screws and nuts,generally referred to as 84, a pair of spaced members SI having the twoparts extending at right angles to each other, and between -which ispivotally mounted, on a stud It, a brush holder 81;

" Thebrushholder lLasshowninPlguresL l and 5, is composed of two piecesof suitable metal fastened together by bolts or studs 38 and 3!, betweenwhich is clamped a brush it. As will be seen, by reference to Figure 1,the two parts 'of the brush holder 31 are long enough to extend over thebands I and I so that, after the brush 4. becomes worn sumciently, orfor any reason The arms 8 of the spider have, at'

becomes broken, the brush holder 31 will contact with the bands 4 and I,which are of insulating material and cannot contact with the track orcommutator surface 8, which would injure the track surface and alsoshort-circuit several turns of the winding. Since the brush holder 31 ispivoted at I, the-brush and holder may oscillate inaverticalplane,sothat thebrush ll will be self-aligning along the tracksurface between the bands 4 and 8. In other words, the brush It will beheld substantially parallel with each and every turn of the winding and,due to the flanged construction of the parts 35, the holder 31 will haveno movement which will take the brush out of its position justdescribed.

As shown in Figure 1, the brush is connected through a flexibleconductor I with a stud 42 to which is connected a cable 43 which passesto the interior of the tubular member i0, and one or more times aroundthe shaft 18, and through an opening 44 in the tubular member Iii, tothe terminal stud 23 (see Figure 3), It is to be understood that thestud is insulated from the member 33.

The necessary pressure of the brush on the 'commutatoror track I isobtained by reason of a spring member 45. The conductor cable 43 is heldin position in the arm I2 by a suitable clip 48., In the form shown inFigure 6, the cable If is carried to the brush holder 31 in a littledifferent manner than shown in Figure 1, in that it passes through ahole 41 in the arm 32 and directly to the intermediate connecting stud42, thereby eliminating-the hole 48 in the member I! (see Figure 5).

In Figures 8 to 11 inclusive, the brush holder and connections aresomewhat different than heretofore described. In these figures, thecable 0 passes through the arm 32 as in Figure 6, but runs directly tothe brush holder. and is fastened thereto by one of the studs or bolts38. As will be seen, by reference to Figures 8 and 11, the back side ofthe brush holder has a semi-circu lar seat formed therein for the roundhead 49 of a stud or pin 50, which is slidably held by the member I! andthe outer end of which is engaged by a spring 5| similar to the spring45, but a little differently shaped. This construction allows the brush40 to oscillate about the head ll of the pin 60 without twisting orweaving, for the same purpose as described with respect to theconstruction shownin Figure 1, 'thus allowing the brush to make contactthroughout its entire length on a conductor of the brush track orcommutator surface I. It should be noted that the arm 32 is providedwith a lug 52 adapted to'engage a stop "on one of the arms of the spider8 so as to stop the rotation of the arm I! after it is turned by thehand-wheel 54.

By. reference to Figure 1, it .is to be noted that there is a spacebetween the lines III which marks the beginning and end of the windingof the transformer, and the stops '2 and I! are arranged on the arm 32and clamp I so as to stop the brush 40 on opposite sides of the saidspace, according to how the arm 3! is turned.

. By reference to Figure '7, it will be noted that the contact end ofthe brush 0 is beveled so that the contact face of the brush issubstantially the width of one of-the conductors, Just the same as inthe heretofore referred to Hunter patents,

wherein the brush is preferably not thicker than the thickness of one ofthe commutator bars illustrated. Furthermore, the brush 4b isconstructed of precisely the same material as the brush described insaid Hunter patents; that is to say, the material is of such a nature asto have sufiiclent resistance in association with the turn of thetransformer that no detrimental short-circuitoccurs when the brushpasses from one conductor to the next, it being understood 'that in thiscondition the brush spans two adjacent conductors, so that the circuitin which the voltage is being regulated is never opened, and little orno fluctuation of current occurs therein. It may be mentioned that thewidth of the track is made compatible with the length of the brush sothe face area will be suflicient to carry the current withoutoverheating and sparking,

The construction of the regulator is such that a plurality of them maybe mounted in tandem by bolts passing through the holes l8 in theextensions or feet H, at the same time providing a longer shaft to gothrough the units, the arm for each regulator being connected to theshaft.

by ,means of the necessary bearing bushings fitting in the tubularmember ll), of a length to correspond to the number of units to beconnected in tandem for multiple or polyphase operation of a pluralityof the-regulators. Such a regulator for a three-phase circuit is shownin Figure 12, wherein the studs 51 are supplied with spacing collars andnuts 58 for holding two of the unit regulators in spaced relation. Thestuds 51 terminate at some point 63 to receive the threaded ends ofcollars 6!, thereby holding all the units in tandem relationship. Thefree ends of the collar Bl may be threaded at 62 for mounting theregulator on a panel, in which case, suitable brace members are engagedby the nuts 59 on the lower ends of the studs 51. Where this type ofregulator is mounted on a stand or base, it may be clamped thereto bythe nuts 59, it being understood that the studs 51 pass through the baseor support member.

It may be noted, in passing, that if the core is made of a single stripof magnetic material as described, I prefer to anneal it after rollingit up, and before the outer insulation and winding is put on.

Furthermore, it may be mentioned that while Figure 7 shows the brush 46with a slightly tapered point, this is not necessary, except where theregulator is of very low capacity and the wire of the transformerwinding is of relatively small diameter. In the larger capacities ofthis type of regulator, where the turns of the winding 3 are of suchsize as to give the brush the necessary mechanical strength at its face,the brush is not beveled.

From what has been said, it will be seen that certain changes may bemade in the details entering into the construction of my improved typeof regulator. It will also be understood that while I prefer to use asingle winding, the winding may be separated into a primary andsecondary,

the brush running on a similarly constructed track on the secondarywinding. If the primary and secondary are used, they may be arranged andconnected so that the brush need only travel over a small portion of theouter periphery of the secondary.

What I claim is:

1. A voltage regulator including an annular core, a. winding surroundingsaid core, with means for making electrical connection thereto, saidwinding being bared on its outer circumferential surface to form a brushtrack, a tubular member centrally located within and passing through thecore, clamping members carried by said tubular member at opposite endsof said core with means for clamping them against the core and winding,a shaft rotatably located within said tubular member and having an armextending radially over one end of the winding, means for rotating theshaft, a brush holder carried by said arm, a brush carried by the holderso as to run on said track, means for making a working electricalconnection to said holder, and means for preventing the holder fromcontacting with the track when the brush wears out or becomes broken. Y

2. A voltage regulator as set forth in claim 1, further characterized inthat said lastmentioned means includes insulating bands on oppositesides of the brush track, the brush holder being of a length to overlapthe bands, and the bands being of a thickness to prevent the holder fromtouching the track when the holder engages the bands.

3. A voltage regulator including an annular core, a winding surroundingsaid cor-e, with means for making electrical connection thereto, saidwinding being bared on its outer circumferential surface to form a brushtrack, a tubular member centrally located within and passing through thecore, clamping members carried by said tubular member at opposite endsof said core with means for clamping them against the core and winding,a shaft rotatably located within said tubular member and having an armextending radially over one end of the winding, means for rotating theshaft, 2. brush holder carried by said arm so as to oscillate in a planeincluding an element of said track, a brush carried by the holder so asto run on said track, and means positioned overthe winding adapted toengage the holder under certain conditions to prevent the holder from,engaging the track.

4. A voltage regulator as set forth in claim 1, further characterized inthat the bottom end clamping member has flanges thereon for mount-- ingthereondevices such as a terminal-connecting strip carrying terminalsfor the winding and brush lead, and a number plate, and furthercharacterized in that said bottom clamping member has feet for mountingthe regulator, and shoulders for receiving and attaching a coverthereto.

5. A, voltage regulator including an annular core, tight fittinginsulation around said core to form a solid support for a commutator orbrush track, an insulated winding over said core and having a spacegoing nearly around its outer circumferential surface .bared to form abrush track, clamping members carried by said tubular member at oppositeends of the core and having spaced arms for engaging the side of thecore and winding bands going around the winding on opposite sides ofsaid track at least to prevent expansion of the winding and movement ofthe commutator or track conductors when pressure is applied to the coreand winding by said clamping members, a tubular member centrally locatedwithin and going through the core, means for tightening the clampingmembers in securing position, a shaft rotatably carried by said tubularmember, means on the shaft for rotating it, an

arm for carrying current from the brush and minal located on said board,thebottom clamping member having flanges on its arms for carrying theterminal board, said arms on the bottom clamping member having shouldersto receive a cover, and also having holes therein for mounting theregulator. T

6. A voltage regulator including an annular core comprising a strip ofmagnetic material arranged in concentric turns initially tightly woundand covered with a tightly fitting cover of insulating material, awinding around the core on said insulating cover, said Winding beingsecurely anchored to the core by spaced binding means and being bared,on its outer circumferential surface in a belt extending nearly aroundthe core and between said spaced binding means, to form a commutator orbrush track, a tubular member centrally located within the core,clamping members carried by the tubular member at opposite ends of thecore and having parts for gripping the sides of the core and winding, ashaft rotatably and removably carried within said tubular member, meansfor rotating, the shaft, an arm mounted for rotation with the shaft, abrush rigging including a holder carried by said arm, a brush carried bythe holder in contact with the surface of said track, the brush beingsubstantially the width of a conductor forming part of the track, andthe holder itself being mounted so as to insure that the brush isselfaligningalong the length of a conductor of the track.

7. A voltage regulator as set forth in claim 6 further characterized inthat said binding means comprises two rings of material preferably ofinsulating tape tightly wound over the winding at opposite sides of thetrack.

8. A voltage regulator as set forth in claim 6, further characterized inthat said brush is seated in a holder which is carried by said arm, sothe brush and bolder can swing about a pivot in a plane including aconductor in said track for the purpose described.

9. A polyphase voltage regulator comprising a plurality of unitsarranged in tandem; each unit including an annular core, a windingsurrounding the core with means for making electrical connectionthereto, said winding being securely bound to the core and bared on itsouter circumferential surface to form a commutator or brush track; atubular member passing through the.

core of each of said units, sets of clamping mem-- bers carried by thetubular member, one set for each unit, at opposite ends of its core,with 'means for clamping them against their respective cores andwindings, ashaft rotatably located within said tubular members andhaving an arm for each unit extending radially over the end of itswinding; means for rotating the shaft; a brush holder carried by each ofthe unit arms, a brush carried by each of said holders to engage itsrespective commutator or track, the said clamping members having feetfor receiving means to anchor the units together in spaced relation.

JOHN L. SCHERMERHORN.

